Process of producing aluminum-magnesium alloys.



No. 881,934. PATENTED MAR. 17, 1908. P. VON KUGELGEN & G. 0. SEWARD.

PROCESS OF PRODUCING ALUMINUM MAGNESIUM ALLOYS.

APPLICATION FILED APR. 27. 1905.

INVENTORS [0% 1 1 J Nor/a ry,

UNITED STATES PATENT OFFICE.

FRANZ VON, KUGELGEN AND GEORGE O. SEWARD, OF HOIA OMBS ROCK, VIRGINIA.

ASSIGNORS TO VIRGINIA LABORATORY COMPANY, OF NEW YORK, N. Y., A (0R- PORATION OF NEW YORK.

PROCESS OF PRODUCING ALUMINUM-MAGNESIUM ALLOYS.

Specification of Letters Patent.

Application filed April 27, 1905.

Patented March 17, 1908.

Serial No. 257,618.

To all whom it may concern:

Be it known that we, FRANZ voN Ki'IGEL- GEN, a subject of the German Em eror, and GEORGE O. S'EWARD, a citizen of t 1e United States, both residing at Holcombs Rock, in.

it is possible to make castings at a dull red heat. These alloys would supersede aluminum were'it not for the high cost of the magnesium, and for the loss of magnesium when the metals are melted together to form the alloy.

Our present invention provides a process by which these alloys can be roduced more cheaply than heretofore. ur rocess is characterized by the electrolytic ecomposition of ma nesium oxid dissolved in a suitable fluorid bath in the presence of a cathode of molten aluminum, or aluminum-magnesium alloy, with which the reduced magnesium alloys; or by the electrolysis of a combine bath of a magnesium compound and an aluminum compound, their reduced metals alloying at the cathode. The electrolytic bath is composed of magnesium oxid, or a mixture of aluminum oxid and magnesium oxid, dissolved in magnesium fluorid and a fluorid of a more electro-positive metal, the bath being of such specific gravity that the alloy produced remains at the bottom.

Our present invention is based upon our process for the production of magnesium characterized by the electrolytic decomposition of ma nesium oxid dissolved .in a molton bath oi a metallic salt or salts; the best bath being of magnesium fluorid and a fluorid of a more electroositive metal. have discovered that tiis process is applicable to the production of aluminum-magnesium allo s by using a cathode of molten aluminum or of such alloy) with which the separated magnesium alloys and remains at the bottom of the electrolytic vessel. We have also found that aluminum oxid is easily dissolved in such a bath, and that aluminum-magnesium alloys are obtained when amixture of aluminum oxid and magnesium oxid is fed to the fluorid bath instead of magnesium oxid alone.

Our process may'be variously practiced,

and the electrolytic cell or vessel may be variously constructed. We will describe in detail one suitable and preferable mode of practicing our process with reference to the accompanying drawing, which shows a suitable electrolytic cell for the purpose, the view being in vertical mid-section.

Referring to the drawing, let A designate a suitable vessel, such as an iron pot, which may have its sides cooled by a water jacket Such cooling would result in a chilled layer B of the electrolyte which would insulate the sides of the vessel so that no current would pass from the electrodes to the sides.

C is the molten metal cathode, which is at first of aluminum and subsequently of aluminun1-mag11esium alloy.

E is the molten electrolyte and F F the anodes of carbon or graphite. A dynamo or other generator G has its positive terminal connected to the anodes F 1* and its negative terminal to the pot A. v

In practicing the process, a suitable quantity of aluminum is placed in the bottom of the vessel and the electrolyte is introduced and melted by the curre'nt. This electrolyte consists of magnesium oxid or magnesium oxychlorid dissolved in a suitable salt, preferably magnesium lithium fluorid. Or magnesium fluorid mixed with some other fluorid of a metal more electroositive than magnesium may be used. he proportions of fluorid salts may greatly vary. of the electrolysis is to decompose the dissolved magnesium oxid, the liberated magnesium' oin to the cathode where it alloys with t e aluminum, so that the cathode becomes an aluminum-magnesium alloywherein the proportion of magnesium is continually increasing. When the desired proportion of magnesium is reached, the alloy is tapped out or otherwise removed from the vessel, and fresh aluminum is added. Magnesium oxid is fed continually into the electrolyte to re lace that which is decomposed.

Instead 0 adding metallic aluminum, the

The eil'ect aluminum may be produced in the cell simultaneously with the magnesium by double electrolysis. To this end it is only necessary to mix aluminum oxid with the magnesium oxid and feed the mixed oxids into the fused bath instead of the magnesium oxid alone. Both oxids dissolve in the bath, and bothare decomposed by the current, freeing both magnesium and aluminum at the cathode, so that the metals alloy continuously. By mixing the oxids in the proper proportions, the resulting alloy can be produced of any desired composition or richness. The proc-' ess is thus rendered substantially'a continuous one, it being only necessary to tap off the alloy from time to time without paying any attention to its composition.

Instead of using magnesium oxid, we may use ma nesium oxychlorid, which is easily obtained free frornwater, is soluble in a fluorid bath, and is decomposed in the same way as magnesium oxid, except that both chlorin and oxygen are liberated at the anode. By the expression magnesium oxid" in our claims, we desire it understood thatmagnesium oxychlorid is included, as well as any other magnesium compound of analogous composition and pro erties.

Our process pro uces the desired aluminum-magnesium' alloys at low cost, and avoids the loss due to melting magnesium and aluminum together to form the alloy.

It is not to be understood from the particularity with which we have described our rocess, that our invention is necessarily imited to the s ecific process described.

Various mo ifications may be made by those skilled in the art, without departure from our invention. The electrolytic cell may be greatly varied in construction.

What we claim is 1. The process of roducing aluminummagnesium alloys, w 'ch consists in electrolyzing magnesium oxid dissolved in a fused salt of low specific gravity in the presence of a cathode of molten aluminum-magnesium alloy with which the separated magnesium alloys.

2. The process of producing aluminumssnesa magnesium alloys, which consists in electrolyzing magnesium oxid dissolved in a fused salt in presence of a cathode of molten aluminum-magnesium alloy with which the separated magnesium alloys.

3. The process of producing aluminummagnesium alloys, which consists in electrolyzing magnesium oxid dissolved in a fused fluorid in the presence of a cathode of molten aluminummagnesium alloy with which the separated magnesium alloys.

4. The process of producing aluminummagnesium alloys, whichconsists in electrolyzing magnesium ox-id dissolved in fused magnesium fluorid and a fluorid of a more electro-positive metal in the presence of a cathode of molten aluminum-magnesium alloy with which the separated magnesium alloys.

5. The process of EZI'OdIlClIlg aluminummagnesium alloys, w ich consists in electrolyzing a combined fused bath of a magnesium compound and an aluminum compound.

6. The process of producing aluminummagnesium alloys, which consists in electrolyzing magnesium oxid and aluminum oxid dissolved in a fused fluorid bath.

7. The process of producing aluminummagnesium alloys, which consists in introducing into a fused bath of magnesium fluorid and a fluorid of a more electro-positive metal, a mixture of magnesium oxid and aluminum oxid, and electrolytically decomposing the same.

8.- The process of producing aluminummagnesium alloys, which consists in introducing into a fused bath of magnesium fluorid and lithium fluorid, a mixture of magnesium oxid and aluminum oxid, and electrolytically decomposing the same.

In witness whereof, we have hereunto signed our names-in the presence of two subscribing witnesses.

FRANZ .V ON KUGELGEN. GEORGE O. SEWARD.

Witnessesv J. H. WEBB, C. OFFERHAUS. 

